1. Field of the Invention
The present invention relates to a magnetic head and to a fabrication process therefor, and more particularly to a magnetic head for high density recording and/or reproduction such as those used in video-tape recorders and still video cameras and to a fabrication process therefor.
2. Description of the Prior Art
An explanation shall be made of an example of a prior art magnetic head having a plurality of magnetic recording and/or reproducing members together with a fabrication process therefor, with reference to FIGS. 1-5.
In FIG. 1, reference numerals 1 and 2 denote half blocks of a magnetic head core. The first half block 1 of the magnetic head core is a rectangular parallelepiped, and has an abutment surface 4 for abutting with the second half block 2 of the magnetic head core on the other side.
The second half block 2 of the magnetic head core has a coil groove 3 formed on the main plane of a parallelepiped, and has abutment surfaces 5 and 6 for abutting with the first half block 1 of the magnetic head core.
The materials in these half blocks 1 and 2 of the magnetic head core (hereinafter referred to as the core half blocks) can be ferrite or Sendust which has a high permeability.
The abutment surfaces 4, 5 and 6 of these core half blocks 1 and 2 are finished with a flat surface, and then a non-magnetic material, for example, Si0.sub.2, is deposited on the surfaces 4, 5 and 6 to form a non-magnetic thin film for forming a magnetic gap 7.
Next, the core half blocks 1 and 2 are adhered to each other via the non-magnetic thin film as shown in FIG. 2, so as to obtain a magnetic head core block having a magnetic gap 7. Then, in order to separate adjacent recording and/or reproducing tracks on a magnetic recording medium, grooves 8a and 8b are formed at specific intervals longitudinally along the block, and at a depth whirh does not cause the blocks to be separated. A shielding plate 9 for separating the tracks is fitted into and secured in these grooves 8a and 8b.
Subsequently, this block is cut longitudinally along a plane shown by a dotted line c--c which intersects with grooves 8a and 8b. Furthermore, the block is cut along planes indicated by dotted lines a--a and b--b so as to obtain a magnetic core member which has the same thickness on either side of the shielding plate 9.
The magnetic core member 1a thus obtained is shown in FIG. 3. This magnetic core member la comprises the shielding plate 9, on both sides of which the magnetic gaps 7 and 7 are positioned to form a single straight line.
Because the interval between tracks, i.e., the thickness of the shielding plate 9, of this magnetic core member 1a is generally narrow on the order of several tens of microns, it is necessary to provide an auxiliary core 10 as shown in FIG. 4 so as to form a space to wind a winding. This auxiliary core 10 is in the form of a parallelepiped having a groove 10a formed on one side surface thereof in order to wind a winding 11. The material of this auxiliary core 10 can be ferrite or Sendust which has a high permeability.
The winding 11 is wound around the coil groove 10a of this auxiliary core 10. Two auxiliary cores 10 each having the winding 11 are adhered to the respective side surfaces of the magnetic core member la in a manner such that the two auxiliary cores 10 are opposite each other as shown in FIG. 5 to form a magnetic ciruit which is magnetically conductive. In this way a magnetic head is obtained.
In a prior art magnetic head having such a structure, the area of the opposing surfaces of the core half blocks 1 and 2 is large, so that there is a disadvantage in that the amount of crosstalk between adjacent tracks is not reduced, even if the material and the shape of the shielding plate 9 are devised.
Furthermore, as shown in FIG. 2, the core half blocks 1 and 2 are cut a plurality of times in various direction so that there is the defect of complexity and high cost in the fabrication process.